Torpedo director



Jan. 7, 1947. E. P. ROSS TORPEDO DIRECT C R Filed June 20, 1941 2 smu -sheet '2 ,GYRO ANGLE 2359. iitbuo l Em lio Patented Jan. 7, 1947 TOBPEDO DIRECTOR Elliott P. Ross, Forest Hills, N. Y., assignor to Ford Instrument Company, Inc., Long Island City, N. Y., a corporation of New York Application June 20, 1941, Serial No. 398,951

This invention relates to apparatus for use in directing the training of torpedo tubes or for use in setting the gyroscope controlling the course of the torpedo, in order that the torpedo shall be given a course such that it will hit a moving target taking into consideration the bearing of the target relative to the firing ship, the relative rate of movement of the target across the line of bearing, the range to the target, the course and speed of the firing ship, the speed of the torpedo and the elapsed time between the moment of obtaining the desired angle from the apparatus and the discharge of the torpedo.

According to the present invention means are provided for observing the bearing of the target relative to the firing ship, and a variable speed device or integrator is provided for continuously generating corresponding values of true bearing,

which are combined with the course of the firing ship to give values of generated bearing relative to the ship which may be compared with the observed value or may be used to drive the sight to keep it pointed at the target. The setting of the rate member of the integrator represents the angular rate of change of bearing of the target when the generated values continuously agree with the observed values or the sight is driven at a rate which keeps it pointed at the target. The elapsed time, which is generally known as dead time, is allowed for by a multiplier which multiplies the rate setting of the integrator by the dead time to give the change of bearing during that time. Means are also provided whereby the product of this multiplication is combined with the present value of bearing to give an advanced value equal to what the bearing will be when the torpedo is discharged. The balance of the solution of the problem is based on this advance value. The angular rate of change of bearing obtained from the rate setting of the integrator is due to the movement of both the target and own ship. This rate of change of bearing is converted to the lateral rate of relative movement across the line of bearing of the firing ship and target by a mechanism which multiplies the angular rate by the range. Since the solution for the torpedo deflection angle requires only the rate of lateral movement of the target, the rate of lateral movement due to the firing ship is deducted from the total lateral rate to give the rate due to the target. The lateral rate due to the firing ship is obtained from a component solver the vector of which is set in accordance with the bearing of the target relative to the firing ship and the speed of the firing ship. From 5 Claims. (Cl. 235-.61.5)

2 this lateral rate of the target and the topedo speed the collision course of the torpedo relative to the line of bearing is readily obtained.

The fundamental features of this invention will be more readily understood and may be car-' ried into efiect by reference to the following description and the accompanying drawings, in which:

Fig. 1 is a diagrammatic representation of the problem solved by the invention;

Fig. 2 is a schematic representation of a form of the invention.

Referring particularly to Fig. 1, the observing station on the firing ship is designated as O, and the line OO represents the centerline of the firing ship. The angle (BSI) is the observed relative bearing of the target measured relative to the centerline (0-0) of the ship. The point Tl represents the observed position of the target and the length of the line O-Tl represents the observed range (RI). The rate of change of bearing due to the relative movement of the target and firing ship is designated as dB which when multiplied by the dead time (tD) gives the angular change of bearing (Dt) during the dead time as expressed in the equation,

Dt=tD-dB (1) The relative bearing of the target at the end of the dead time is designated as BS and is expressed by the equation,

BS=BSl+Dt The relative position of the target at the end of the dead time is designated T and the line OT represents the range (R) at the end of the dead time. The course of the firing ship (CO) is measured from a line O-N, representing north, to the centerline OO' of the firing ship. The true bearing of the target at the point T is designated as B and is expressed by the equation,

The rate of change of bearing (dB) is preferably obtained by generating or integrating values of true bearing (B) which are compared with the corresponding observed values. When the generated values of bearing continue to remain equal to the observed values it is known that the rate set on the integrator i correct. The lateral rate of relative movement (RdB) of the target and own ship is obtained by multiplying the angular rate (123) by the range (R) as expressed mathematically in the equation,

3 The lateral rate (RdB) is also equal to the algebraic sum of the components of rate of movement of the target and firing ship, which are designated as XT and X respectively. This relation is expressed by the equation,

RdB=XT+XO The value of the component of movement X0 of the firing ship is expressed by the equation XO=SO-sin BS (6) in which SO represents the speed of the firing ship. Since the speed SO and the angle BS are known the Value of the component X0 is readily obtainable and since the total relative lateral rate (RdB) is known the value of the component XT is obtained by transposing Equation 5 as follows:

XT=RdB-XO (7) The deflection angle (DT) or ofiset of the torpedo course from the bearing of the target at the time of discharge is obtained as a function of the cross component rate of movement (XT) of the target and the torpedo speed (SG) by solving the equation is 8G (8) since for small angles the angle is proportional to the sine.

The collision path of the torpedo and a target, having a cross component rate of movement equal to XT, as obtained by the solution of Equation 7 is represented by the line OC |--C which is offset from the line OT by the angle DT. The direction of the line O--C|C relative to the centerline (OO') of the firing ship, which is known as gyro angle (BQ) is expressed by the equation,

BG=BS+DT (9) It is to be noted that the actual course and speed of the target are not required to be known as the cross component of movement XT. of the target has been otherwise obtained. The target may be on any course and speed which would give the cross component XT obtained, for example, the value of the component XT may have been due to a target having a speed ST and on a course CT relative to north, as indicated by the line T-N, or it may have been due to a target having a speed STI on a course CTI. In the case of the first example the point of intercept or collision of the target and torpedo is at the point C and in the second case it is at the point Cl Referring now to Fig. 2, the observed relative bearing of the target (BS!) is obtained by a sight I mounted for training by a hand-crank 2 through shafting 3 and gears 4. An integrator 5, consisting essentially of a constant speed member 6, a rate member I, and a variable speed output member 8, is driven by a constant speed motor 9 connected to the constant speed member 6 by gears Ill. The rate member I is positioned by a handcrank II and shafting |2 which actuates a gear l3 meshing with a rack |4 connected to the rate member I. The position of the rate member I is indicated by a dial I5 connected to the shafting |2 by worm l6. The dial I5 is read against a fixed index I! to indicate rate of change of bearing A multiplier I8 multiplie dead time (tD) and rate of change of bearing to give deflection (Dt), due to dead time, in accordance with Equation 1. One input of multiplier I8 is the arm l9 which is swung about the center 20 by the toothed sector 2| which is positioned in accordance with the setting of rate of change of bearing (dB), as represented by the rotation of shafting I2, by gears 22. The second input to multiplier I8 is the screw 23 which positions a pin 24 relative to the center 20 in accordance with the dead time (tD) The screw 23 is driven by a shaft 25 through a universal joint in line with the pivot 26. The shaft 25 drives a dial 26 by means of a worm 21 mounted on shaft 25. The dial 26 is read against a, fixed index 28 to indicate dead time (tD) and is positioned by a hand-crank 29 connected to the shaft 25. The output sector 30 of the multiplier I8 is positioned by the pin 24 acting through a slot in a crossshaped member 3| which is pivoted at one end to the output sector 30 by a pin 32 and at the other end to an arm 33 by a pin 34. The output sector 30 is pivoted about a pin 35 and the arm 33 is pivoted about a pin 36.

Shafting 31 is positioned by the output sector 30 in accordance with the deflection (Dt) due to the dead time (tD). Shafting 3! and shafting 3, the rotation of which represents the observed relative bearing (BSI), are connected through differential 38 to drive shafting 39 to represent relative bearing (BS) as indicated in Equation 2. The output member 8 of the integrator 5 rotates one member of the differential 40 in accordance with increments of true target bearing (B). A second member of the differential 40 is positioned in accordance with ships course (CO) by shaft 4| and a servo-motor 42 which is controlled by a, receiver motor 43 through contacts 44. The receiver motor 43 is positioned in accordance with ships course (CO) by a transmitter (not shown) at a master compass. The third member of differential 40 actuates a shaft 45 and one member of a differential 46 in accordance with generated relative bearing (BS) as seen from Equation 3. A second member of differential 46 ispositioned by shafting 39 the rotation of which represents observed relative bearing (BS). The third member of differential 46 actuates a shaft 41 to which is attached a pointer 48 which is read against a fixed dial 49. It will be seen that when the pointer 48 45 remains stationary the rate member I of the integrator 5 is set to the correct value of rate of change of bearin (dB).

The two inputs of multiplier 50, which is in all respects similar to multiplier I8, are set in accordance with the rate of change of bearing (dB) by gear 5| which is actuated by shafting I2 and in accordance with range (R) by shaft 52, which is positioned by a hand-crank 53. The shaft 52 drives a dial 54, through a worm 55, to indicate range (R) when read against the fixed index 56. The output sector positions shaft 51 through gears 58 to represent the lateral rate of relative movement (RdB) as will be seen from Equation 4.

The lateral rate (X0) or cross component rate of movement due to the firing ship is obtained from a component solver 59, the vector member of which consists of gear 60, having a radial slot in which a pin 6| carried by a sliding block 62 is positioned by a screw 63. The screw is rotated by a knob 64 to position the pin 6| at a radius, from the center of the gear 60, proportional to the speed of the firin ship. To facilitate this setting an index line is provided on the block 62 which is read against the ship speed scale 65 graduated on the gear 60. The gear 60 is angularly positioned by the shafting 39 in accordance with the relative bearing (BS). A single component slide 66 is positioned by the pin 6| to represent the lateral rate X0 in accordance with Equation 6.

The shafting 61 is positioned to represent the lateral rate X0 by the rack 68 on the slide 66. The two input members of differential 69 are positioned by shaft 51 and shafting 61 so that the output member positions shafting to represent the lateral rate XT of the target as seen from Equation 7.

The dividing mechanism H is in all respects similar to the multipliers l8 and 50 except that the input and output through the sectors are interchanged. The shafting 10 positions the crossshaped member 12 through the sector 13 in accordance with the lateral rate of movement XT of the target and the pin I4 is positioned in accordance with the torpedo speed (SG) by handcrank 15 and shaft 16. The value of the torpedo speed is indicated by a dial H, which is driven by a worm 18 mounted on shaft 16. The dial TI is read against a fixed index 19. The output arm 80 and sector 8| are positioned in accordance with the torpedo deflection (DT) as seen from Equation 8.

Shafting 82 which is positioned by sector 8| in accordance with the torpedo deflection (DT) drives a dial 83 by worm 8 1 to indicate target deflection when read against a fixed index 85. The torpedo deflection (DT) represented by rotation of shafting 82 is combined in differential 86 with the rotation of shaft 39 to drive the shafting 81 and the dial 88, through the worm 89, relative to the fixed index 90 in accordance with the gyro angle BG as in Equation 9.

Instead of the pointer 48, the shaft 41 may be provided with a hand-crank by which shaft 41 will normally be held stationary so that the rotation of shaft 45 will rotate shafting 39 through differential 46. Shafting 39 will then rotate shafting 3 through differential 38 to drive the sight I. Instead of the hand-crank 2 the operator will use the hand-crank on shaft 41 to correct or shift the position of the sight and the rate at which the sight is driven will be controlled by the hand-crank H.

Various other modifications will be apparent to those skilled in the art, for example, the sight may be located at a distance and connected to the computing mechanism by electrical transmission. Continuous values of range may be generated, in addition to bearing, and range values may be predicted to determine the run of the torpedo. The output values of deflection and gyro angle may be transmitted to the torpedo station and corrections may be made for curvature of the path of the torpedo when discharged from a fixed tube.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a torpedo director, means positionable in accordance with the observed bearing of a target relative to a reference line on a firing ship, an integrating device including an input member driven at a constant speed, an output member and an adjustable rate setting member the position of which represents the rate of movement of the output member, means movable in accordance with the true direction of the reference line, means actuated by the last mentioned means for modifying the movement of the output member to cause the modified movement to represent the bearing of the target relative to the reference line, differential means interconnecting the first mentioned means and the modified movement of the output member of the integrating device, said differential having a third member the movement of which represents the difference between the modified movement of the output member of the integrating device and movement of the first mentioned means and indicates the adjustment of the rate member required to cause the rate of movement of the output member to agree with the rate of movement of the first mentioned means, means settable in accordance with the range between the firing ship and the target, multiplying means having two input members, one actuated in accordance with the position of the rate setting member and the second in accordance with the position of the range settable means, said multiplying means having an output member the position of which represents the lateral rate of relative movement between the firing ship and the target, means settable in accordance with the lateral rate of movement due to the firing ship, second diiferential means interconnecting the output member of the multiplying means and the last mentioned settable means, said second differential having an output member the position of which represents the rate of lateral movement of the target, means for determining the torpedo deflection angle including two input elements one of which is movable in accordance with the position of the output member of the second differential and the second is settable in accordance with the torpedo speed, said determining means having an output element the position of which represents the torpedo deflection angle, and means actuated by the last mentioned output element and the position of the first mentioned means for indicating the relative gyro angle.

2. In a torpedo director, means positionable in accordance with the observed bearing of a target relative to a reference line on a firing ship, means settable in accordance with the angular rate of relative movement between the firing ship and the target, means settable in accordance with a desired time interval, a multiplying mechanism having two input elements positioned by the settable means respectively, and an output element the position of which represents the product of the values represented by the position of the input elements, means settable in accordance with the range between the firing ship and the target, a second multiplying mechanism having two input elements positioned by the last mentioned settable means and the means settable in accordance with the angular rate of relative movement between the firing ship and the target, respectively, and an output element the position of which represents theproduct of the values represented by the position of the input elements, means settable in accordance with the rate of lateral movement due to the firing ship, differential means actuated by the last mentioned settable means and the position of the output element of the second multiplying mechanism, said differential having an output member the position of which represents the rate of lateral movement of the target, means for determining the torpedo deflection angle including two input elements one of which is movable in accordance with the position of the output member of the differential and the second is settable in accordance with the torpedo speed, said determining means having an output element the position of which represents the torpedo deflection angle, means positionable by the first mentioned means and the output of the first mentioned multiplying mechanism to represent an advanced bearing of the target and means actuated by the output element which represents the torpedo deflection angle and the last mentioned means for indicat ing the relative gyro angle.

3. In a torpedo director, means positionable in accordance with the observed bearing of a target relative to a reference line on a firing ship, a variable speed mechanism including an input member, an output member, and a rate member positionable to control the rate of movement of the output member, means for comparing the movement of the output member with the movement of the first mentioned means, a member positionable in accordance with the course of the firing ship, means actuated by the last mentioned member for modifying the comparing means, means settable in accordance with the range between the firing ship and the target, a multiplying mechanism having an output'member and two input members, one actuated in accordance with the position of the rate member and the second in accordance with the position of the range settable means, a component solver having a vector member jointly positionable by the first mentioned means and in accordance with the speed of the firing ship, and having a component member positioned thereby to represent the lateral rate of movement due to the firing ship, differential means interconnecting the component member and the output member of the multiplying mechanism, said difierential means having an output member the position of which represents the rate of lateral movement of the target across the observed bearing, and computing means having an output element representing the torpedo deflection angle and input elements movable in accordance with the position of the output member of the difierential means and with the torpedo speed respectively.

4. In a torpedo director, means positionable in accordance with the observed bearing of a target relative to a reference line on a firing ship, a variable speed mechanism including an input member, an output member, and a rate member positionable to control the rate of movement of the output member, means for comparing the movement of the output member with the movement of the first mentioned means, a member positionable in accordance with the course of the firing ship, means actuated by the last mentioned member for modifying the comparing means, a multiplying mechanism having an output member and two input elements, one of which is positioned by the rate member and the second in acinput members, one actuated in accordance with the position of the rate member and the second in accordance with the range of the target from the firing ship, a component solver having a vector member jointly positionable by the output member of the differential means and in accordance with the speed of the firing ship and having a component member positioned thereby to represent the lateral rate of movement due to the firing ship, second differential means interconnecting the component member and the output member of the second multiplying mechanism, said second differential means having an output member the position of which represents the rate of lateral movement due to the target, computing means having an output element representing the torpedo deflection angle and input elements movable in accordance with the position of the output member of the second difierential means and with the torpedo speed respectively, and means jointly actuated by the torpedo deflection determining means and the output member of the first mentioned differential means for indicating the course of the torpedo relative to the reference line.

5. In a torpedo directing mechanism, means settable in accordance with the angular rate of relative movement between a firing ship and a target, means settable in accordance with the range between the firing ship and the target, multiplying means having two input members respectively actuated in accordance with the settable means and an output member the position of which represents the lateral rate of relative movement of the firing ship and the target across the line of bearing of the target from the firing ship, a component solver including a vector member settable in accordance with the speed of the firing ship and the direction of movement of the firing ship with respect to the bearing of the target and a component slide positioned by the vector member to represent the rate of lateral movement of the firing ship across the line of bearing to the target, differential means actuated in accordance with the position of the output member of the multiplying means and said component slide to position a member to represent the lateral rate of movement of the target across the line of bearing to the target, and a dividing mechanism havin an input element movable in accordance with the position of the last mentioned member, a second input element settable in accordance with the torpedo speed, and an output element connected to be positioned in accordance with the first input divided by the second input to represent the torpedo deflection angle.

ELLIOTT P. ROSS. 

